Method of making butt-weld pipe.



UNITED STATES ATJENT OFFICE.

PETER PATTERSON, OF MCKEESPORT, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBECOMPANY, OF PITTSBURG, PENNSYLVANIA,I A CORPORATION OF NEW JERSEY.

METHOD OF'MAKING BUTT-WELD PIPE.

SPECIFICATION forming part of Letters Patent No. 714,735, dated December2, 1902.

V Apulication filed February 14, 1902. Serial No. 94,119. (No model.)

T0 a/ZZ whom, it may concern: p

Be it known that LPurnR PATTERSON, a resident of McKeesport, in thecounty of Allegheny and State of Pennsylvania,.have invented a new anduseful Improvement in Methods of Making Butt-Weld Pipe; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof.

p My invention relates to the manufacture of butt-Weld tubing, itsobject being to provide a method of making-the same from U-shaped orapproximately tubular skelp and by which the edges of the skelps can bebrought to a welding heat throughout their length, while the bodies areeasily and with certainty held sufficiently stiff' to force together theabutting edges into welding contact when passing through thewelding-bell, and also to make possible the employment of a soft heatinstead of the rash heat usually employed in the manufacture ofbutt-weld tubing from fiat plates while heating the skelps in suiiicientnumbers to keep the welding mechanism in rapid operation, and so makinga large output possible.

To these ends myinvention consists, generally stated, in chargingaU-shaped or approxiy mately tubular skelp longitudinally through therear end of the furnace and into a protecting-recess formed in thefurnace-bed, raisingthe upwardly-extending edges of the skelp to awelding heat while the body rests in the recess and is thus protectedfrom the furnaceheat, and thereafter drawing the heated skelplongitudinally through the front of the furnace and through aWeldingbell, it being practicable by establishingfa plurality ofparallel protecting-recesses in the furnace-bed .having acharging-opening i at the rear and a withdrawing-opening 5 at theopposite end thereof. I also employ any suitable drawing apparatus 6,adapted to draw the heated skelp from diiferent parts of thefurnace-bed, that shown being the ordinary swinging drawbenchhaving thebell-holder 7 atrits front end and the traveling draw-chain 8. Suitablewelding-bells 9, tongs 10, and hooks 11 for connecting the tongs anddraw-chain are also employed. The bed of the furnace is composed ofsand, gravel, or other suitable material capable 0f withstanding a highheat, and extending longitudinally along the same are a pluralityof,protecting-recessesl, corresponding to the number of skelps to beheated, the drawing showing ten of these recesses for ten processions ofskelps, it being understood that the number of recesses employed willdepend upon the heat of the furnace and the thickness and character ofthe material operated on. These protecting-recesses form predeterminedlongitudinal paths for the skelps through the f urnace-chamber. Beforecommencing operations the protecting-re-- emerge from the finishing-passof the rollingmill, the plates being sheared to length before bending orthe skelps sheared after bending.v

In the practice of the invention the furnace is preferably maintained atwhat is known as a slow or soft" welding heat for the reasons abovestated. The skelps are charged longitudinally and successively throughthe rear opening 4: into the protecting-recesses 12 of the furnace-bedand rest there with their edges 15 extending upwardly and their bodies16 resting in the recesses while being heated, and the heat of thefurnace raises the edges of each skelp to the desired welding heat whilethe the body is shielded or protected from the direct heat of thefurnace by the recess in which it rests. As each skel p reaches theproper heat its front end is grasped by tongs or other suitable deviceand drawn longitudinally through the front of the furnace and through awelding-bell, and so welded into tubing. A fresh cold skelp can becharged into the furnace in the place of the one withdrawn, and toobtain the largest output it is preferable to charge the fresh skelpbefore the heated one is entirely withdrawn from the furnace. As thebody 16 of the U-shaped skelp is bent to or nearly to the shape desiredin the finished tube and the remaining work of theweldingbell is tobring the upwardly-extendin g edges l5 into abutting and weldingcontact, it is evident that it is only necessary to raise the body tobending-heat to enable it to conform to the shape of the bell and thatthe stiffer the body portionthe greater will be the pressure betweenthecontacting edges and the more perfect the Weld obtained. The continualfeeding of fresh cold skelps into the protecting-recess serves to chillthe recess, and so aids in holding the body portion of the skelpsstiffer for forcing the edges together in passing through thewelding-bell. y In this Way of working a slower and softer heat can beemployed than is employed to the best advantage in heating flat platesfor welding in' bells, and therefore the heating period and the criticalperiod during which the edges are at proper welding heatcan both belengthened and the danger of producing imperfectlywelded tubes reduced.This result can be attained without reducing the output, because theU-shaped skelps occupy but little space on the furnace-bed, and asufficient number of heated skelps can be provided for rapid Weldingoperations. The softer heat which can be employed also extends the lifeof the furnace, which is Very inj uriously acted upon and quickly burnedout by the high rash or oxidizing heat necessarily employed in ordinarypractice to obtain a large output.

What .I claim as my invention, and desire to secure by Letters Patent,is-

1. The method of forming butt-weld tubing consisting in charging a' U-shaped or approximately tubular skelp longitudinally through the rearof the furnace and into a protectingrecess in the furnace -bed, raisingthe upwardly-extending edges of the skelp'to welding heat while the bodyrests in the recess and is thus protected from the furnace-heat, andthereafter drawing the heated skelp longitudinally through the front endof the furnace and through a welding-bell.

` 2. The method of forming butt-weld tubing consisting in taking aU-shaped or approximately tubular skelp, heating'the same while the bodyis somewhat protected from the heat, whereby the projecting edges of theskelp are raised to a welding heat while the body remains comparativelystiff, and thereafter drawing the heated skelp through a weldingbell. f

In testimony whereof Lthe said PETER PAT- TERSON, have hereunto set myhand.

PETER PATTERSON.

Witnesses:

Fp. W. WINTER, ROBERT C. To'rTEN.

